GSI

GSI may refer to:

* Geographical Society of Ireland
* Geological Survey of Ireland
* Geological Survey of India
* Geological Survey of Iran
* Geological Survey of Israel
* Geographical Survey Institute of Japan
* Geological Strength Index
* Geophysical Service Incorporated, a petroleum exploration corporation
* Gesellschaft für Schwerionenforschung, a German ion research laboratory
* Global Subsidies Initiative, an initiative by the International Institute for Sustainable Development
* Gemological Science International, a gemstone assessment laboratory
* GSI Commerce, a shopping website design company
* GSI Outdoors, an outdoors cookware company
* Graduate Student Instructor = Teaching assistant
* Grid Security Infrastructure, a specification for tamperproof computer networks
* Government Secure Intranet, the system for managing secure access to e-mail and other services for UK government departments
* GIST Support International, An international patient organization for the support of individuals facing gastrointestinal stromal tumor.
* Good Shepherd Institute
* Guangzhou Shipyard International, a shipbuilding state-owned enterprise in the People's Republic of China